Steam-engine.



LE GRAND SKINNER.

STEAM ENGINE..-

APPLICATION, FILED MAR. 251 1914.

"Patented Nov. 2, 1915.

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. gwuentoz E GRAND SKINNER.

STEAM ENGINE.

APPLICATION F-ILED MAR. 25. 1914.

Patented Nov. 2, 1815.

2 SHEEN-SHEET 2.

.@ Corzierw oil/44W lmmwooen admission to exhaust.

IIE'GRAND SKTNNER, 0F ERIE, PENNSYLVANIA.

STEAM-ENGINE.

Specification of Letters. Patent.

t res,

Patented Nov. 2, 1915;

Application filed March 25, 1914. Serial No. 827,109.

To all whom it may concern:

Be it known that I, Ln GRAND SKINNER, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented certain new and useful Improvements in Steam-Engines, of which the following is a specification.

Thisinvention relates to that type of engines known as uniflow engines in which the steam travels in only onedirection from ()rdinarily, in such engines, the steam enters the cylinder at the ends, and, after cut-off and expansion have taken place, is exhausted at the end of the stroke through exhaust ports arranged around the middle of the cylinder, which ports are uncovered by the piston, which thus operates as an exhaust valve. steam, consequently, flows in but one direction, that is, from the ends of the cylinder toward the middle. Or it may enter the cylinder at the middle, and exhaust at the ends. These engines usually operate condensing, but to preserve tlieunifiow effect and at the same time to be able to operate non-condensing with small clearances, the SkinnerlVilliams Patent No. 1,033,280 disclosed an engine of the uniflow type which, in addition to the central exhaustports, is provided with additional exhaust valves located between the central exhaust ports and the ends of the cylinder, which additional or auxiliary valves are operated to, relnain open, after the exhaust ports are closed by the passage of the piston thereover, whereby heavy compression,-wl1en running non-conde'nsing, is prevented and the engine is available for non-condensing use. In the engine disclosed ,111 said patent, the auxiliary exhaust ports are in communication with the exhaust pipe or passage leading from the middle exhaust ports, and accordingly one pipe or passage takes care of the exhaust from all the ports.

The object of the present invention 'is to make possible the exhausting of the steam from the cylinder through the middle ex-- haust ports into an exhaust pipe at atmospheric pressure, or against the usual back pressure in a heating system, where by such exhaust steam may be utilized for heating or other purposes, and at the same time, or as soon as the piston has coveredthe central exhaust ports on the compression stroke, the auxiliary exhaust valves are opened to communicate through. pas- The hausting the steam at atmospheric or heating pressure through the central exhaust ports is concerned, and as a condensing engine by exhausting into a condenser the vapor remaining in the cylinder after the piston has covered the central exhaust ports on the compression or return stroke, and so timing the opening of the auxiliary exhaust valves that they will not open until the piston on the return or compression stroke has covered the middle exhaust ports, and so timing the closing of the auxiliary exhaust valves that they willclose shortly after the piston has covered the auxiliary exhaust' port on that side, or at such point as to give suitable compression.

A modification is provided by means of which the engine can operate entirely as a condensing engine, as might beadvisable where exhaust steam is not needed for other purposes, as in the summer, by means of connections controlled by valves between the middle exhaust ports and the auxiliary exhaust ports, or connected to a condenser. It will be seen that, by separating the two exhausts, when release takesplace the whole voluine of steam-is available for heating purposes, without withdrawal of pressure from the pressure side of the cylinder, still maintaining, if desired, proper vacuum on the exhaust side of the p ston, by means of the auxiliary exhaust ports connected to the condenser. Practically all of-the steam'in .through the auxi iary exhaust valves tothe condenser. I

=Anembodiment of the invention is, illustrated in the accompanying drawing, in

which:-

Figure 1 is a longitudinal section ofthe the cylinder. Fig. 2 is a side elevation, partly in section, of a modification in which valved passages are provided to connect all the exhaust ports when desired. elevation of Fig. 2. Fig. 4 represents a combined indicator diagram, where the unshaded portion is the card that would be ob tained from a non-condensing uniflow or central exhaust engine. The cross-hatched portion represents the additional area secured by operating this engine utilizing the exhaust from the central port, and condens ing the residual as illustrated in Fig. 1 and hereinafter described. Fig. 5 represents an indicator diagram from a condensing unifiolv or central exhaust engine, where all the exhaust is led to the condenser as hereinafter described with reference to the modification illustrated in Figs. 2 and3.

Referring specifically to the drawing, 6 indicates the cylinder, 7 the piston, 8 the middle or main exhaust ports and 9 the inlet ports, the inlet valves being omitted.

' 10 is the piston rod. I The middle exhaust ports communicate with an annular passage 11. leading to a main exhaust pipe 12 which may be extended to a heating apparatus or to other places where low pressure steam may be utilized, as forheating feed water or the like.

The auxiliary exhaust ports 13 are preferably located. between the middle exhaust .ports and the ends of the cylinder, preferably in substantially the same relation or position as that described in the patent above referred to, but could be located else- I where. The passages leading from these ports are separated from the main exhaust passage'by walls 14 and are connected by branch pipes 15 to an auxiliary exhaust pipe 16 which will or may be connected to a condenser (not shown). The auxiliary exhaust passages are, controlled by puppet valves 17 which may be operated by any suitable valve gear (not shown), contained in the casings 18. The particular mechanism for operating the auxiliary exhaust valves is immaterial.

In operation, when the piston uncovers the middle exhaust ports 8 practically a full exhaust takes place, the steam conducted through the pipe 12 being available for heating or other purposes. The auxiliary exhaust valve remains closed during the expansion period and until the piston, on the return stroke, covers the ports 8, when compression would begin, but the auxiliary exhaust valve is then opened, permitting remaining oiadditional exhaust through the auxiliary exhaust ports 13 at that end of the cylinder, to the condenser, under such vacuum as may be maintained. After the piston covers theauxiliary exhaust ports 13,

I the valve may be closed but under certain conditions it may be advisable, and in any event it is possible, and Within the scope of Fig. 3 is an end.

the invention, to close the auxiliary valve before the piston covers said port. Necessarily, if the auxiliary valves are locat where the pistonwould not operate to cl e said ports, the ports would be controlled solely by the valves. On the next stroke the same operation is eft'ected at the other end of the cylinder, in a double-acting engine.

It will be seen that all the steam is withdrawn from the exhaust side of the piston, and none from the pressure side, so there is no loss of pressure and full economy of steam is preserved, and a relatively small condenser may be used, since it has to talte care only of the residual steam remaining after the main exhaust. Y

The engine will give a diagram showing a drop to atmosphere, or substantially so, following the opening of the main exhaust ports, and a further drop to vacuum following the opening of the auxiliary exhaust port which opens communication to the condenser. The increased area of such a dia-- gram, as shown in cross-hatched diagram,

Fig. 4e, indicates an increased effect of pressure with the same amount of steam supply, with of course increased indicated horse power and increased economy over the noncondensing engine. But if the steam exhausting through ports 8 is not needed for other purposes, the engine may be operated full condensing by the modification shown in Figs. 2 and 3 in which a connection 2% is provided between the main exhaust pipe 12 and the auxiliary exhaust pipe 16, said connection having a valve 25, which when opened will connect all the exhaust passages to the condenser, another valve 26 being placed in the exhaust pipe 12, beyond the cross connection referred to, which valve when closed will cut off the communication from the middle exhaust to the atmosphere or heating apparatus.

The engine may be operated full non-condensing by closing valve 27 in exhaust line 16 to condenser, and opening valves 25 and 26.

I claim 1. A uniflow engine cylinder having a middle exhaust port and auxiliary exhaust ports toward the ends of the cylinder, the middle port being connected to pressurecontaining devices, and the auxiliary ports being connected to a condenser, and valves controlling the auxiliary ports and timed to' remain closed during the expansion period and to open after the middle port has been closed on the exhaust stroke. 2. A uniflow engine cylinder having a middle exhaust port connected to a heating system, and valved auxiliary ports located between the said middle portahd the ends of the cylinder and connecte "to a condenser.

3. A am engine cylinder hav ng a midtem, at

' type having dle exhaust port and a conduit therefrom to devices receiving steam at low pressure, an

auxiliary ports located between the middle port and the ends of the cylinder, a conduit leading from said auxiliary ports to a condenser, and a valved cross connection be- 4L A steam engine having a middle exhaustport and auxiliary exhaust ports located between themiddle port and the ends of the cylinder, and a \casing extending along the cylinder and having a middle exhaust passage communicating with the middle port-and adapted for V heating system or the like, and also having separate auxiliary exhaust passages at the ends communicating with said auxiliary ports and adapted for connection to a condenser, and valves located in said auxiliary passages and controllingthe same.

5. port and valved auxiliary exhaust ports, means for delivering steam from the main port to a heating or other low pressure systhe end of the power stroke, and means for Withdrawing residual steam separately at a lower pressure through the auxiliary ports after themain port is closed, on the exhaust or return stroke.

6. A reciprocating steam engine of the a main exhaust port and auxiliary exhaust ports between the main port and the ends of the cylinder, means for exhausting the steam through the main port at the end of the power stroke of the piston, against atmospheric or other low pressure and then holding the auxiliary port closed during the power stroke, and then 'exhausting the residual steam through the auxiliary port, under vacuum, during the return stroke of the piston.

connection to a A steam engine having a main exhaust the exhaust through "the main'port closing said port and means for- 7. An engine cylinder having a main exhaust port connected to a pressure-containing system, the opening and closing of said port being effected by movement of the pis ton, and having a valved auxiliary exhaust port connected. to a condenser.

' 8. A reciprocating steam engine having a main exhaust port, controlled by the piston, and auxiliary exhaustport's, and means for exhausting residual steam through an auxiliary exhaust port to a condenser, after the piston hascovered the main exhaust port on the return stroke.

9. A steam engine having main and auxiliary exhaust ports, steam through the main exhaust port after expansion on the -powerstroke, and means for exhausting residual-steam through an auxiliary port to a condenser on the return stroke.

means for exhaustingv 10. A steam engine having main and auxilary exhaust ports, meansfor exhausting certain pressure, at the latter part of the power stroke, and means for exhausting residual steam through an' auxiliary port on the return stroke, at a lower pressure than 11. A reciprocating steam engine provided with means for exhausting steamtherefrom at a certain pressure at the end of the power stroke of the piston and means for exhausting residual steam therefrom at a lower pressure, on the return stroke of the piston.

In testimony whereof, I afiix' my signature in presence of two witnesses.

LE GRAND SKINNER.

Witnesses: v i

M. L. BUNTING, J. P. Eoimm.

steam through the main exhaust port at a 

